Sliding clasp fastener



Dec. 7, 1954 E. SANDER 2,696,032

sLIDING CLASP FASTENER Filed July 3, 1951 United States Patent O M 2,696,032 SLIDING CLASP FASTENER Ernst Sander, Prien am Chiemsee, Oberbayern, Germany, assiguor to Giovanni Mastracchi-Manes, Milan, Italy Application July 3, 1951, Serial No. 234,950

1 Claim. (Cl. 24201) In the patent application of Ernst Sander, S. N. 181,738 filed August 28, 1950, a sliding clasp fastener has been described in which an underengaging and an overengaging strip, both made of resilient material, are in mutual gripping engagement with each other, one of the strips being in addition provided with a bead and an undercut surface for clasping the edge of the other strip in the interlocking position of the sliding clasp fastener.

The present invention relates to a sliding clasp fastener which is particularly suitable for bags, containers or the like to obtain a water-tight and gas-tight sealing thereof. According to the invention one of the strips of the fastener is provided with a bead extending over the entire length of this strip substantially in the outer side thereof and being of the same cross-section throughout its length. This bead may have a circular cross section and is in connection with the strip by means of a web of reduced thickness. The other strip is formed with a groove of the same cross section as the bead. In this groove the bead of the first mentioned strip is introduced. According to the invention the ends of the overengaging and underengaging strips are joined inseparably with each other and with the walls of the bag, etc. so that for opening the sliding clasp fastener it is only opened in its central portion between the firmly connected ends by forcibly separating the two strips held in mutual engagement. In order to obtain a tight sealing a slider is provided for pressing the bead into the groove of the mating strip in order to obtain a clasping engagement.

By so designing the sliding clasp fastener according to the invention it is possible to close it notwithstanding the mutual engagement of the ends of the two strips since it does not require upon closing the preparation of a clasping engagement as is necessary with the sliding clasp fastener described in the aforesaid patent application S. N. 181,738. The bead of the one strip is pressed into the groove of the mating strip of the slider and is not slid therein. This shaping of bead and of groove assures a correct interlocking sliding motion of these two elements and simultaneously a tight sealing so as to permit its application for waterand gas-tight closures.

ln order to reliably prevent a tilting movement of the strips upon closing the sliding clasp fastener, the slider running in grooves provided on the one hand in the underengaging strip and in the overengaging strip projects so deeply with its ends into said grooves that the engaging surfaces thus being formed are capable of effectively taking up the torque produced in tilting. In this way the flange of the one strip is introduced into the undercutting of the other strip so that the fastener will operate safely.

In the accompanying drawing one form of embodiment of the invention is illustrated by way of example.

In the drawing, the sole gure is a cross-section of the 2,696,032 Patented Dec. 7, 1954 beaded strips of the embodiment in engagement with each other, the front face of the slider being visible.

The overengaging strip 1 carries a bead 2 of circular cross section which in the interlocking position of the sliding clasp fastener is pressed into the longitudinal groove 3 of the underengaging strip 4. The underengaging strip 4 is formed with a rectilinear undercutting 5 for engagement with a correspondingly shaped flange of the overengaging strip 1 upon closing the sliding clasp fastener. The slider 6 effects by means of the presser 7 secured thereon the introduction or the pressingin of the bead 2 into the groove 3 and thus establishes the connection between the overengaging and underengaging strips 1 and 4 respectively.

The slider 6 is guided with its downwardly and inwardly bent ends 8 and 9 within the grooves 10 and 11 respectively, of the overengaging and underengaging strips l and 4, such guiding grooves being deep enough as to avoid during the closing of the sliding clasp fastener a tilting movement of the two strips 1 and 4 relative to each other and thus of the slider 6 which would prevent the making of a connection. This is accomplished by the taking up of the torque produced thereby on the engaging surfaces of the ends 8 and 9 of the slider in the grooves 10 and 11. At the same time the undercutting 5 of the underengaging strip 4 is brought into the desired interlocking engagement with the strip 1 which again prevents tilting of the slider 6. By designing the bead 2 of the strip 1 and the corresponding longitudinal groove 3 in the mating strip 4 according to the invention a perfectly water-tight and gas-tight joint is assured, the cross section of the bead 2 being capable of presenting any other continuously shaped outlines behind the narrower web 12. The underengaging strip 4 is secured on the ribbon of fabric 14 and the overengaging strip 1 on the ribbon of fabric 13.

I claim:

A water and gas-tight clasp fastener for an article such as a pocket, pocket book or the like, comprising an under-engaging and an over-engaging elongated member of resilient material, said members complementing one another to a substantially rectangular cross-section with flanges extending laterally at the base thereof, said overengaging member having throughout its length a crosssection of which one portion extends the length of said rectangle opposite said base and of which another portion extends the width of said rectangle, said first portion including a bead with reduced neck extending the length of said first member and projecting towards said base and said second portion having an inner undercut face, said under-engaging member having in its face opposite said base a first longitudinal groove fittingly receiving said bead and neck, and having a corner fitting said undercut face, each of said members having in its outside a lateral longitudinal second groove of substantial depth in a plane parallel to said base, said overengaging member having a face opposite and parallel to said base, said last mentioned face being exposed to receive pressure from the web of a slide engaging said second grooves with inward directed flanges.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,013,071 Sipe Sept. 3, 1935 2,355,816 Morner Aug. 15, 1944 2,558,367 Madsen June 26, 1951 

